Law is the body of rules and standards that govern human behavior. It shapes politics, economics, history and society. It also serves as a mediator of relations between people.

Laws are made by government, social institutions or individuals to regulate their behavior. They can be statutes enacted by legislative bodies or executive agencies, regulations issued by administrative bodies or established by judges through precedent.

There are four major purposes of law: establishing standards, maintaining order, resolving disputes, and protecting liberties and rights. Some legal systems serve these purposes better than others.

The basic divisions of law are criminal, civil, and administrative. Criminal laws are statutes enacted to maintain order in society and punish the offender. Compensating individuals who have been injured physically or economically is a civil law problem.

Criminal defenses include necessity, duress, and intoxication. Necessity defenses are especially important for defending against violent offenses, such as assault.

Judicial interpretations of law are known as “case law.” In common law systems, decisions by courts are explicitly acknowledged as “law” on equal footing with statutes adopted through the legislative process and with regulations issued by the executive branch. This is often referred to as the doctrine of stare decisis (“to stand by”) because these decisions bind lower courts and future decisions of the same court to assure that similar cases reach similar results.

Common law legal systems have a body of case law developed by courts throughout the centuries. These cases were compiled by professional jurists and are more detailed than the less formal legal codes of Roman law.